The coralline mosses are subject to great variation: and altho’ there are several really distinct species, yet they run so into one another, that it is no easy matter to fix upon the real specific distinctions, in many instances. Some species are perfectly white; others have the extremities of the branches reddish, some brown, and others almost black. The common coralline moss in Lapland not unfrequently grows to be several inches long, and even a foot high.
The tubular or hollow branched coralline mosses are not the only kinds upon which the rein-deer will feed. Almost all the lichens are abundantly more plentiful in those northern, than in these more southerly climates. There are several species with solid branches; one, which Dillenius calls The crisp warty Alpine coralloides[88], which is almost as plentiful as the common sort, and is equally acceptable to those animals[89]. It was before observed, that, in defect of these mosses, the black mane usnea is a substitute equally acceptable to those animals.
Another of the most remarkable and useful plants of this division is the orchel[90], or argol, as it is commonly called. This enters more into œconomical uses among us than any other of the whole genus. How considerable an article it forms in the dying trade, in which its uses are various and extensive, is very well known. Its tinging property has been known from ancient times; and some of our most celebrated botanic writers are of opinion, that it was used as a dye even in the days of Theophrastus. That father of botany mentions a fucus, which, he says, grew upon the rocks about the island of Crete; and that they dyed woollen garments of a purple, or rather a red colour, with it. It grows on the rocks by the sea-coast in many parts of the Archipelago, and in the Canary Islands; from whence we generally import it, as well as from the Cape Verd, which afford it in plenty. The demand for orchel is so great, that Mr. Hellot[91], of the Royal Academy of Sciences, informs us, they gather yearly, upon an average, from the isle of Teneriffe 500 quintals, which amounts to 25 ton weight; from the Canary Islands 400 quintals, from Forteventura 300, from Lancerota 300, the same from Gomera, and from Ferro 800.
The way of manufacturing the orchel for the uses of dying, was for a considerable time a secret in few hands; but it is now done in London, and other parts of Europe, to great perfection. Mr. Ray, from Imperatus, gives a brief account of the process[92]. Micheli has since delivered a more exact detail of it. His, at least, seems to be the method[93], which the dyers at Florence used. From both these accounts, urine and pot-ash appear to be the principal ingredients used in extracting its colour.
Many other plants of this genus contain the same tophaceous matter as the orchel; and upon trial have been found to strike a good colour. Micheli, after he has related the preparation of the orchel, suggests the same thing; and M. Hellot, in the treatise before mentioned, tells us, there are many other mosses, which will give as good a colour as the orchel. In fact, he adds, that M. Bernard de Jussieu brought him some from the forest of Fontainbleau, which, upon experiments with urine and lime, took a purple colour. In the sequel of this memoir we shall point out some of these kinds. M. Hellot has given us a process, which he made use of for discovering whether any of these lichens would yield a red or purple colour. It is as follows: “Put about two drachms of any of these lichens into a little glass jar: moisten it well with equal parts of strong lime-water, and volatile spirit of sal ammoniac; tie a wet bladder close over the top of the vessel, and let it stand three or four days. At the end of this time, if the lichen is likely to answer, that small quantity of liquor, which you will find in the glass, will be of a deep crimson red; and the plant will retain the same colour when the liquor is all dried up. If neither the liquor nor the plant have taken any colour, it is needless to make any further trials with it.” This process is simple and easy, and well worth observation by all who are disposed to prosecute experiments of this nature: and indeed it is worth the trial, whether several lichens, which we have plentifully enough in England, would not answer in this respect.
3. Lichenes pyxidati.
Such as consist of a firm tough flexible matter, formed into simple tubular stalks, whose tops are expanded into the form of little cups.
This division contains the cup-mosses of authors; the second order of coralloides of Dillenius; great part of the first order of lichens in Haller; the 7th, 8th, 9th, and 10th order in Micheli; and the lichenes schyphiferi of Linnæus. Dr. Hill has constituted a genus intirely of these cup-mosses, under the name of pyxidium.
They are common with us on heaths, and other dry and barren places. Some of them are proliferous, even to the third degree, and form a very beautiful appearance. Some have tubercles on the edges of the cups, of a beautiful scarlet colour.
The cup-moss[94] was a long time in great and established use for coughs, and especially for the whooping cough in children; for which it was long accounted a specific. To this end it was given in various forms. Gerard and Parkinson recommend the powder to be taken for several days together. Dr. Willis was particularly one of its patrons. He has given us[95] several forms for its exhibition, as that of the powder, a decoction, and a syrup from it.